CI: Add check for php 7.2

* PHP 7.2 was released. Added a lint check to test if the current code is able to run on it.
10 jobs for ci-php7.2 in 2 minutes and 37 seconds (queued for 1 second)
Status Job ID Name Coverage
  Lint
passed #5972
lint:lint-php5.4

00:00:48

passed #5973
lint:lint-php5.6

00:00:28

passed #5974
lint:lint-php7.0

00:00:47

passed #5975
lint:lint-php7.1

00:00:48

passed #5976
lint:lint-php7.2

00:00:38

 
  Codesniffer
passed #5977
codesniffer

00:00:52

 
  Unit
passed #5978
unit:testBasic

00:00:34

passed #5979
unit:testRead

00:00:54

passed #5980
unit:testReadAssertFail

00:00:51

passed #5981
unit:testUserProperty

00:00:55